Underreamer



oct. 14|, 1924.

W.' R. WlLBER UNDERREAMER Filed May 17. 1923 I Z/, will? IllIlIF l//W -mnnmllll n l 35 /l s atto: um,

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Patented Oct. 14, 1924.

UNITED STATES WILLIAM R. WILBER, F

THERMOPOLIS, WYOMING.

UNDERREAMER.

Application filed May 17,

To all whom t may concern.:

Be it known that I, IWILLIAM R. WILBER, a citizen of the United States, residing at Thermopolis, county of Hot Springs,`and State of iVyoming, have invented certain new and useful Improvements in Underreamers; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the characters of reference marked thereon, which form a part of this specification.

This invention relates to improvements in under-reamers of the type used in drilling oil wells.

In the drilling of deep wells, it is essential that casings shall be inserted into the well at least as far as bedrock so as to keep the walls from caving in and to keep water from entering the well. In order to insert the casing into the well, it is necessary to ream the opening below the casing so that it will be at least as large in diameter as the casing. It is, of course, necessary that the underreamer shall be of a larger diameter than the inside of the casing and the reamer must, of course, be inserted and removed through the casing. This makes it necessary that the reamer shall be expansible so that it may be introduced and removed.

I am aware that many different kinds of under-reamers have been made. Most of them, however, have the cutters held in expanded position by means of springs or by other means which leave openings which permit the mud to enter and clog the parts to such an extent that it is difcult to remove the tool.

It is the object of this invention to produce an under-reamer that shall be so constructed that it can be readily collapsed and held in collapsed position for the purpose of inserting the same into a casing, and which will automatically expand to operative position when the reamer reaches the under side of the casing.

It is a further object of this invention to produce an under-reamer in which the cutting lugs shall be held in expanded position by means of a wedge or block that automatically moves into position between the cutter lugs as soon as the reamer reaches a position below the casing.

In order to be able to withdraw the 1923. Serial No. 639,545.

reamer, it is, of course, essential that the block or wedge shall be removed from its position between the cutters so as to permit them to collapse in order that the reamer may enter and pass through the casing and it is my object to so construct the reamer that this will automatically take place whenever the reamer is pulled upwardly into the casing.

It is a further object of this invention to so arrange and construct the parts that the cutters shall rest securely on the body por tion of the reamer so that the shocks and jars will not cause any undue strains on their pivots. I also provide the cutters with lugs which co-act with notches in the body portion to prevent the pivots from being sheared when the cutters are subjected to strains in the operation of removing the reamer.

The above objects and others, which will appear as the description proceeds, is attained by means of a construction which I will now describe in detail, reference for this purpose being had to` the accompanying drawing in which the preferred embodiment of the reamer is shown, and in which:

Fig. l is a longitudinal section of my reamer, taken on line 1 1, Fig. 5, with the parts in operative or expanded position;

Fig. 2 is a section similar to that shown in Fig. l, but taken on line 2 2, Fig. 6, and showing the parts collapsed and in the position which they occupy in passing through the casing;

Fig. 3 is a side elevation of the reamer with the parts collapsed and showing how they are held in position by means of a ring;

Fig. 4 shows a side elevation of the reamer as it appears in operative position, the casing shoe and part of the well being shown in section;

Fig. 5 is a section taken on line 5 5, Fig. l;

Fig. 6 is a section taken on line 6 6, Fig. 2;

Fig. 7 is a section similar to that of Fig. 1, but to a slightly larger scale and shows one of the cutter lugsremoved; Fig. 8 is a side elevation of the part shown in Fig. 7, but with parts broken away;

Fig. 9 is a bottom plan vi'ew looking in the direction of the arrow 9 in Fig. 7, but showing the two cutters in place; and

Fig. 10 is a section taken on line 10 10, Fig. 7.

The same reference numbers will be used to designate the same parts throughoutthe several views. i

Numeral 1 represents what I will designate as the body member of my reamer which is a cylindrical steel bar of the proper diameter provided at one end with a threaded lug 2. The body member is provided with an axial opening 5l which receives the locking device 4 which consists of a rod having acentral portion 5 of a diameter which permits it to slide freely in the opening 3. The upper end 6 is of a smaller diznneter and passes through a coil spring 7 whose outside diameter is such that it can freely slide in theopening 3. Securedto the very end of the part 6 is a round nut 8-which may be held .from rotation by a rivet or other suitable means. At the point of juncture between the parts 5 and 6 there is a shoulder 9. f The spring 7 abuts its ends against the nut 8 and the shoulder 9. Thelower end of the part 5 is slightly tapered and terminates in a wideflattened portion 10 having 'a head 11 which serves to hold the cutters in operative position. The portion 6 is provided with a: transverse slot 12 nearfthe shoulder 9 and the body member is provided with'a corresponding slot 13. A key 14 is inserted through these slots and the spring 7 rests thereonso that the tension thereof tends to move the locking device upwardly. The key 14 has a lug 15 which engages the Walls of the opening 3 and prevents the key from sliding out. A short distance below-the slot 12 is a slot 16 for the reception of a key 17 which slides in a slot 18 in the body member 1. On diametrically opposite sides of the member 1 and in the plane Vof the key 17, l provide grooves 19 for the reception of slides 20. The bottoms of the grooves 19 are curved somewhat asshown in Figs 1 and 2 and the inner edges of the slides are si1ni larly curved. The slides 2O have corners or shoulders 21 which project out beyond the surface of the cylinder a distance of onehalf inch or more when the parts are in the position shown in Fig. 1, the distance from the tip of one shoulder 21 to the other eX- ceeding the diameter of the casing. When the slides 2O are moved downwardly to the position shown in Fig. 2, they will, of course, move the key 17 and the locking device ina downward direction compressing the spring 7 slightly during this movement.v As `the slidesmove downwardlytin the slots 19, the shoulders 2l move towards each other, due to the inclined surfaces referred to. By the simple expedient of slipping a ring 22 over the slides in the manner shown in Fig. 2 they will be held from moving back. The ring 22 has an internal diametery substantially equal to that of the casing and has an opening (notshown) so that .itl may be' removed from about the cable after lit has served its r purpose. QLWhen ithe; parts :are vin collapsed therefor.

position, like that shown inFigs. 2l and 3,

the reamer'may be inserted into the casing and as the top of the casing strikes the ring 22, the latter is shoved oft' from the slides and the inside of lthe casing substituted To the lower end of the body member are secured two cutters 23 and 24 which are pivoted to the pins 25. The end 26 of the cutter is curved on the arc of a circle concentric with the pivot pin 25 and the surface of the body member is similarly curved at the same radius so that as the cutters move about their pivots, their ends will slide on the curved surface and be in contact therewith and therefore any endwise force will not have to bge resisted by thel pins 25, but will be taken up Vby the surfaces at 26. The. lower ends ofthe cutters are pro-4 vided with -cutting heads 27 which are shaped somewhat as shown in-Figs. ,7and 9, their outer edges being curved on thearcof a circle whose diameter is-equal to thediameter of the hole to. be 'reamed Owing to the fact that the cutting heads are subjected to the action of grit and sand, whichrwe'ars them away very rapidly, they are made with removable wearing shoes 28. These shoes arev made of hard steel properly tempered and are secured by means of dove-tailed p ortions 29V which cooperate with a simil-arly shaped groove in thehead 27, all as shown and described in my co-pending application,

Serial No. 603,324, filed'November 25, 1922.v

The heads 27 have shoulders 30 .which contact with the endsBl ofthe body member so that the shocks experienced during operation are resisted by the surfaces of` the shoulders, as well asv the ends 26. This makesthe parts almost as strong as if they were forged from a solid piece.

The cutters carry lugs 32 on their inner sides and these cooperate withthe cavities 3-3 in, the` body member and resist` any 4forcethat tends to pull the cutters out of the holder and which might otherwise shear the pins 25. Whenthe reamer is .insel-ted into and removed from the casing, thekcutters slide along the inside of the casing )and are constructed with outwardly curved portions 34 'of hardened steel which are held in place in doivetail shaped transverse groovesl These wearing shoes may ,be replaced when they .become too badly worn and: inv this manner the cutter may beused for a much klonger time. In ,fachby lreplacing the cutter' `shoe 28 and 'the [wear shoe 34, the remaining portions of" the l cutter may be used indelinitely. fllhe cutters are held in expanded position by means 'of the head 11 which forms the bottom kportion of thelo'cking device. ,This-head is off such width that it lits snugly between .the-:inner sur'facesof the cutters .in the manner shown in Figs. 1, 4 and 9, `and hlasitssides.curved in `the manner indicatedby the numeralf in Fig. 9. The edges of the curved sides 35 extend beyond the fla-t sides of the head 11 and form shoulders 36 which embrace the sides of the cutters in the manner shown in Fig. 9 and prevent the shoes 28 from sliding in vthe grooves. The lower end of` the locking device carries two `springs 37 which engage with the inner surface of the cutters and tends to move them' outwardly into operative position. When the parts are collapsed as shown in Figs. 2 and 3, the springs 37 will hold the cutters spread so that they must be held in collapsed -position by some means, (not shown), while the reamer' is inserted into the casing. rPhe slides 2O have shoulders 38 and are held in place by means o-f removable plates 39, (Fig. 5).

The reamer being assembled and constructed in the manner described, operates in the following manner:

The parts normally assume the position shown in Figs. 1, 4 and 7 in which position it is, of course, impossible to insert the reamer` into a casing of the size used in a well of the diameter for which the reamer is made. Before the reamer can be inserted in the casing, the parts must be moved into the posit-ion `shown in Figs. 2 and 3. This is accomplished b-y moving theJ slides 2O downwardly against the key 17 Auntil the head 11 projects below the cutter surfaces 28. A ring 22 is then put into place in the manner shown in Fig. 3 and this prevents the slides from moving back and consequently holds the locking device in the inoperative position. In order to insert the end of the reamer into the casing, the lugs v23 and 24 must be moved inwardly against the action of the 'springs 37 and held in this position until they are inserted in the casing. This can be done by hand. When the reamer has been lowered until the ring strikes the upper end of the casing, the ring is forced to remain.

When the end of the reamer emerges from the casing, the springs-37 will move the cutters into open position and when the slides emerge the spring 7 will function and pull the head 11 up into locking position, shown in Figs. 1, 4 and 7 It is evident that when the parts are in operative position, the cutters will be positively held against collapsing and at the same time the head 11 and the curved sides will prevent mud from entering into the reamer body.

When it is desired to remove the reamer,

it is merely necessary to pull the same upwardly into the casing. The projecting lugs 40 serve to center the reamer in the casing and as the shoulders 21 of the slides 20 strike the lower edge of the casing shoe 41, they will move downwardly, forcing the locking device out of locking position so that when the cutters reach the casing, they are free to move inwardly into the position shown in Fig. 3.

Having non7 described my invention, what I claim as new is:

1. An under-reamer comprising a body member having -an axial opening; a locking device in said opening, said device having a portion of reduced diameter; a spring surrounding said reduced portion; a key slot in the body member and in the locking device; a key passing through said slot and forming an abutment for the spring; a second key slot in said locking device; a key slot in the body member, a key passing through said slots; a sliding member on each side of the body member, said sliding members engaging the ends of the last named key and adapted to move the same and to cause the locking device to be moved against the tension of the spring, a pair of diametrically opposed cutters pivotally connected to the body member and a head on the end of the locking device adapted to engage between the cutters to hold the same in operative position.

2. An under -reamer comprising, in combination, a body member having -a longitudinal opening; a locking device in said opening; a key passing through the body member and the locking device, said locking device being slidable with respect to said key; a spring abutting said key and adapted to hold the locking device in retracted posi tion; a second key projecting through the body member and through the locking device, said key having a longitudinal movement with respect to the body member; slides secured in grooves in each side of the body member and adapted to engage the ends of said key, said slides having portions projecting beyond the outside of said body member; a plurality of cutters pivotally connected to the body member; and a locking head on the locking device, said head being adapted to fit between the cutters when they are in expanded position` In testimony whereof I affix my signature.

WILLIAM R. VVILBER. 

